Sash windows are very popular in North America. Typically, such a window comprises a window frame made of wood in which are mounted glazed sashes which can slide in the frame along a generally vertical axis. The glazing element of the sashes may be simple, double or triple and sealed depending upon the desired degree of thermal insulation.
To facilitate cleaning and repair of a sash window, it has been suggested to provide the window with a device allowing to tilt the sliding panel inwardly of the building to ease access to the outer face of the panel. Although this idea is interesting, it is difficult to put in practice because the device allowing for the translatory motion and the rotation of the sash in the window frame is complex and in most cases, it does not guarantee a good thermal insulation.
The following U.S. Patents illustrate various attempts made by the past to design such a system:
______________________________________ .sup. 988 277, MEIXEN March 28, 1911 2 361 551, LEVYN October 31, 1944 2 987 783, GRIFFITH June 13, 1961 3 399 490, HETTINGER September 3, 1968 ______________________________________
Generally speaking, none of the windows disclosed in these patents is entirely satisfactory because they are difficult to manufacture or do not meet the required standards for air-infiltration and thermal insulation which are important factors for countries with a harsh climate during the winter.